Changing patterns in the epidemiology of β-thalassemia

692 | Eur J Haematol. 2020;105:692–703. wileyonlinelibrary.com/journal/ejh 1 | INTRODUCTION β-thalassemias are a heterogeneous group of hereditary hemoglo- binopathies characterized by defects in the β-globin chain of hemoglobin and autosomal recessive inheritance. Homozygous or compound heterozygous forms have an imbalance in the production of α- and non–α-globin chains, resulting in ineffective erythropoiesis and decreased production of normal hemoglobin A. 1 Patients with β-thalassemia major have severe chronic hemo- lytic anemia and require regular blood transfusions from early childhood. 1-3 Chronic blood transfusion therapy is typically com- bined with iron chelation therapy (ICT) to prevent complications due to iron overload, such as cardiac morbidity, liver disease, and endocrine dysfunction. 1-3 Patients with β-thalassemia intermedia have symptoms in be- tween carriers and those with β-thalassemia major: Anemia is often moderate, but patients may still have morbidity due to ineffective erythropoiesis and hemolysis, including ulcers, pulmonary hyperten- sion, and pain. Some patients require occasional blood transfusions, although less frequently than patients with β-thalassemia major. 1,2 Historically, the prevalence of β-thalassemia has been highest in the Mediterranean region, the Middle East, and Southeast Asia and lowest in Northern Europe and North America. 4 Due to migration patterns, β-thalassemia is increasingly more common in non-endemic regions, Received: 2 June 2020 | Revised: 26 August 2020 | Accepted: 27 August 2020 DOI: 10.1111/ejh.13512 REVIEW ARTICLE Changing patterns in the epidemiology of β-thalassemia Antonis Kattamis 1 | Gian Luca Forni 2 | Yesim Aydinok 3 | Vip Viprakasit 4 This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. © 2020 The Authors. European Journal of Haematology published by John Wiley & Sons Ltd 1 First Department of Pediatrics, National and Kapodistrian University of Athens, Athens, Greece 2 Centro della Microcitemia e Anemie Congenite e del Dismetabolismo del Ferro, Ospedale Galliera, Genoa, Italy 3 Department of Pediatric Hematology and Oncology, Ege University Hospital, Izmir, Turkey 4 Department of Pediatrics & Thalassemia Center, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand Correspondence Antonis Kattamis, National and Kapodistrian University of Athens, Thivon & Mikras Asias Street, 11527 Athens, Greece. Email: [email protected] Funding information Bristol-Myers Squibb Company Abstract β-thalassemia major is an inherited hemoglobinopathy that requires lifelong red blood cell transfusions and iron chelation therapy to prevent complications due to iron overload. Traditionally, β-thalassemia has been more common in certain regions of the world such as the Mediterranean, Middle East, and Southeast Asia. However, the prevalence of β-thalassemia is increasing in other regions, including Northern Europe and North America, primarily due to migration. This review summarizes the available data on the changing incidence and prevalence of β-thalassemia as well as factors influencing disease frequency. The data suggest that the epidemiology of β-thalassemia is changing: Migration has increased the prevalence of the disease in regions traditionally believed to have a low prevalence, while, at the same time, prevention and screening programs in endemic regions have reduced the number of af- fected individuals. Various approaches to prevention and screening have been used. Region-specific prevention and treatment programs, customized to align with local healthcare resources and cultural values, have been effective in identifying patients and carriers and providing information and care. Significant challenges remain in uni- versally implementing these programs. KEYWORDS beta-thalassemia major, incidence, epidemiology

Changing patterns in the epidemiology of β-thalassemia

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